--- Leroy van Logchem <[EMAIL PROTECTED]> wrote: > Andrea Arcangeli wrote: > > On Wed, Aug 22, 2007 at 01:05:13PM +0200, Andi Kleen wrote: > >> Ok perhaps the new adaptive dirty limits helps your single disk > >> a lot too. But your improvements seem to be more "collateral > damage" @) > >> > >> But if that was true it might be enough to just change the dirty > limits > >> to get the same effect on your system. You might want to play with > >> /proc/sys/vm/dirty_* > > > > The adaptive dirty limit is per task so it can't be reproduced with > > global sysctl. It made quite some difference when I researched into > it > > in function of time. This isn't in function of time but it > certainly > > makes a lot of difference too, actually it's the most important > part > > of the patchset for most people, the rest is for the corner cases > that > > aren't handled right currently (writing to a slow device with > > writeback cache has always been hanging the whole thing). > > > Self-tuning > static sysctl's. The last years we needed to use very > small values for dirty_ratio and dirty_background_ratio to soften the > > latency problems we have during sustained writes. Imo these patches > really help in many cases, please commit to mainline. > > -- > Leroy >
while it helps in some situations, I did some tests today with 2.6.22.6+bdi-v9 (Peter was so kind) which seem to indicate that it hurts NFS writes. Anyone seen similar effects? Otherwise I would just second your request. It definitely helps the problematic performance of my CCISS based RAID5 volume. Martin Martin ------------------------------------------------------ Martin Knoblauch email: k n o b i AT knobisoft DOT de www: http://www.knobisoft.de - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
